A thermo-mechanical damage model for thermal crack propagation in brittle materials

To address the challenge of modelling intricate crack patterns in brittle materials, this study introduces a novel damage framework with thermo-mechanical coupling. By integrating thermal effects within a unified energy variational framework, the model incorporates an innovative damage variable that explicitly accounts for thermal deformation and accurately characterises the topology of thermal cracks. The explicit thermo-damage variable and governing equations are directly derived from the variational functional, enabling efficient resolution of thermal fracture problems by focusing solely on displacement and temperature fields. Furthermore, the proposed framework demonstrates the potential for extension to other multi-field coupled fracture problems driven by environmentally induced strain. A series of simulations, including purely mechanical as well as 2D and 3D thermo-mechanical scenarios, validate the model's capability to effectively capture intricate crack behaviours.